Ni(II)-modified solid substrates as platform to adsorb His-tag proteins

LAURA E. VALENTI; VITOR L. MARTINS; ELISA G. HERRERA; ROBERTO TORRESI; CARLA E. GIACOMELLI

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2013 vol. 1 p. 4921 - 4921

his work investigated a simple and versatile modification to a solid substrate to develop electrochemical bio-recognition platforms based on bio-affinity interactions between histidine (His)-tagged proteins and Ni(II) surface sites. Carboxylate (COO)-functionalized substrates were prepared in multiple steps, initiated with an amino-terminated self-assembled monolayer (SAM) on polycrystalline gold. Surface enhanced Raman spectroscopy (SERS), quartz crystal microbalance with dissipation monitoring (QCM-D) and contact angle measurements were used to follow the modification process. Upon completion of the modification process, the surface COO-Ni(II) chelate complex and the coordination mode used to bind the His-tag proteins were characterized by X-ray absorption near-edge spectroscopy (XANES). Finally, the electrochemical stability and response of the modified substrates were evaluated. The versatility of the modification process was verified using silica as the substrate. QCM-D